Automatic telephone system



June 30, 1925.

C. J. ERICKSON AUTOMATIC TELEPHQNE SYSTEM Filed Sept. 7, 1920 IZ'LT UB.H ur E her a n. guns I I Patented June 30,1925." 3

PATENT OFFICE.

UNITED STATES CHARLES J. manor, 0!. (EIOAGO, ILLINOIS, LBSIGIIOB IO Au'ron'rrc unc'rnro comm, OI CHICAGO, ILLINOIS. A. GGBPOI-AI'IOI'OI minors.

AUTOILA'I'IG mun SYBTEI.

Application fled September 7, 1990. Serial Io. 408,541.

To all whom it may concern:

Be it known that I, Cnnunm J. Emoxson, a citizen of the United States of America, and resident of Chi in the county of (look and State of I ois, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a clear,.concise, and, exact descri tion. 7

y invention relates in general to an automatic telephone system and more particularl to an improved automatic tele hone of the type known as a se ector switch, that is one which has access to a plurallty of trunk lines divided into groups and which may be numerically operated to select a'desired group of trunk lines, and then 0 rate automatically to select an idle trunk ine in the group, and extend a connection thereover.

In the est a selector switch of the standard type as been given access to ten trunk lines In a level or grou that is it nii ht ste ten times automatical y over a lev of ten trunks, and if more trunk lines were necessary, then the switch must take more than ten steps, which operation would require too great an expenditure of time.

My invention, which is in the nature of an improvement on the selector switch disclosed in the atent to Jacobson No. negates, gran Sept. 14, 1920; has for its ob ect an improvement in the operation of the same to ther with the revision of an im rovedre ay known as a untfield relay, which is adapted to perform certain flmctions in such a switch as will he more fully disclosed hereinafter.

Since the operation of my improved selector switch is very similar to that of the selector switch disclosed in said prior patent it will be unnecessary to describe harem the detailed operation of the circuit arrangement. I will, however, describe fully the operation of the shuntfield relay, its functions and certain other improved features and in agenare] way, the mode of circmt operation of my improved switch.

Referring now to the drawings: In Fig. 1 I have shown a calling subscriber A, havmg a rotary line switch 0 of the well known rotary t ,individual to his line, which is operated i select an idle one of a number of first selectors, one of which is shown at E p energized singly and which selector, is of the well known Keith, Erickson switch of the side switchless ty with the addition of certain circuits w ch adapt it to operate in accordance with the feature of my invention.

Referring now to of m improved rela This relay is m up 0 two coils 1 an 2 ri 'dly fastened to the heel piece 6. This hee piece is merely a continuation of the frame 5 bent at right angles (Fig. 3) and constitutes art of the magnetic circuit of the rela ivoted at one end of the frame 5 is the armature 4.- of the relay, contnoll' the springs 7. At the up r end of the colls'l and 2 is a soft iron piece 3 which is fastened to the core of both magnets. It will thus be seen that this relay constitutes practically a horeshoe electromagnet having the two coils 1 and 2 with a pole piece 3 which is permanently attached. Now if either one of these coils is it is readily apparent that magnetic flux will be set up m a. circuit from the core of either coil throu h the heel piece 6, the core of the other co then through the le piece 3, to the core of the coil energized. Consequently the coil will have no attraction whatsoever on the armature 4, which will remain in its normal position. Now if both coils 1 and 2 should be energized at the same time flux will be set up in a totally different magnetic circuit, that is of coursefpresupposing that the energizing current flows in the same direction in both coils, from coils 1 and 2 through the heel piece 6, the frame 5 and the armature 4. erefore the armature 4 will pull up and shift the s rings 7 into their .ofl' normal position. aving described my improved relay and its operation, I will now explain how this is incorporated in the invention disclosed in the above mentioned patent.

While in Fig. 1 I have shown a lurality of batteries is will be understood t at there is but preferably 323. battery having its positive le groun Refern g now to Fig. 1, I will describe '0!) of my improved in general the o selector switch. on the subscriber A removes his reoeiver to initiate a call the rotary line switch 0 operates in the usual, and well known manner to select an idle trunk line leading to a selector E, and exres 2 and 3 I have .shown a front and si 0 view respectivel tendthesubscribelslinetothelinerelay of the switch. Bela 25 on energizing com letea the circuit 0 slow acting relay 26, w ch on attractin its armature places ground (1: on the trunk 27 m the usual manner. As the subscriber operates his dial for the first digit of the dethe line rela 25 responds to thee andclosingoiliis looptooperate the vertical magnet 29 in series with 28, which maintains its armature atsen'm of impulses, beacting y.

29ino stepsthewipers 39 to 44 inclusive to some level of bank contacts from which trunk lines lead to the de sired exchange or switches of any desired type. Itistobeunderstoodthatwipers 40, 41 and 43 are line and private wipers of one set, having access to one bank of one hundred contacts, while wipers 39, 42, 44 are the {rivals and line wipers of another set whic have access to a separate bank of a hundred contacts, both sets of wipers being mounted on the same shaft and moving to er.

f t wilidescribe the opei'latiialn o rmgs These springs mig t e @113 a pair of of normal ztrgnngs but they are controlled by e vertical and releasethatlsassoonasthe verticalmagnetis ls- 5M flmspl'lngsaomake, andassoonasthereleasemagnetisenerglued the springs break contact. These springs may be operated the double dog of any Strow switch. S plings which are 0 rated e double-dog of a switch are own in t patent to Martin, No. 1,109,650, granted Sept. 1, 1914 Beta again to the operation of the switch. y 28 on a its armature completes a circuit for both coils of relay 29. This relay is identical to the one illustrated in Figs. 2 and 3 and will therefore attract its armature and lock itself energized over a circuit extending from ground G, lower armature of relays 33 and 34, conductor 31, upper make springs of relay 29, through ho coils of said relay in multiple, springs 30, which are now closed, break 32 of rotalgamagnet 35 to battery. 0w as soon as y 28 deenergizes, which will take place as soon as the first series of impulses w a circuit is then completed for the ro magnet 35 extending from ground G springs 36, conductor 37, all normal sp 32, springs 38 lower make springs of y 29, thence through the rotary magnet 35 to be magnet will operate to rotate the shaft carryingwipers39to44inclusiveontothe first two trunk in the lernzlh and at the sametimeo esprings32 uso 'ng the holding circuit of relay 2e, wm il de energizes. The further rotation of the ttery. The rotary ed nueaoo switch depends on whether or not both trunk lines are busy. Supposin this is the case, the private wipers of bot sets will .find ground and a circuit will be completed for both coils of relay 29, which will operate to close the rotary magnet circuit over the same circuit as previously described. This alternate operation of relay 29 and the rotary me at 35 will continue as long as both tr are busy. The operation of the switch when only one is busy is somewhat different. It will be readily seen that only one coil of m et 29 will have a direct circuit for it w ile the other coil will have a circuit completed for itself in series with one or the other of relays 33 or 34 depending on which trunk is idle. As explained before, rela 29 is so constructed not to operate under t ese conditions, but the rela 33 or 34 energized in series with one of e coils of relay 29 will operate, extending the subscribers line over the idle trunk line. Should both trunk lines be idle both relays 33 and 34'energize in series with both coils of relay 29. Relays 33 and 34 are so arranged that each opens the circuit of the other. Thus only one of them will remain energized and the subscribers line will be extended over only one trunk line.

It has been mentioned above that as soon as the release magnet 45 of this switch operated the springs 30 were separated. Now should the wipers 39 to 44 inclusive, in releasing encounter 2 busy trunk lines simultaneously, relay 29 might again operate and interfere with the release of the switch by a ii the springs 30 were not opened when the release ma et ener It will t erefore be seen that I have provided a very eflicient type of automatic selector switch which will test 20 trucks in the same time it took previousl to test -10, together with other features dlsclosed in the specification.

Having fully described and ascertained the features of my invention what I consider to be new and desire to have protected by the Letters Patent will be pointed out in the ap ended claim.

FVhat I claim as my invention is:

1. In a telephone system, an automatic switch, trunk lines acciissibie thereto, a

ary magnet, a test re ay or said switc 1, means for making certain trunk lines bus means for operating said switch to test a pair of trunk lines simultaneously, a circuit for energizing said relay including groundtest contacts of busy trunk lines when said switch attempts to make connection therewith to o to said rota magnet t. cause said switch to test ano er pair 0 trunk lines simultaneously, means for I'(.4 leasin said switch, and means for opening! said mentioned circuit during restoracompleting the rotary magnet circuit,-

Hill

tion to normal to prevent any further 0 erasaid switch, and means for rendering said 10 tion of said rotary magnet 1n case any usy testing means ineffective durin the release trunk line is encountered. to prevent any false operation 0 said switch 2. In a telephone system, trunk lines, an in case the said testing means engages a busy 5 automatic switch accessible to said lines, trunk line.

testing means in said switch for locating Signed by me at Chicago, Cook County, 15 trunk lines not in use, said testing means Illinois, this 1st day of September, 1920. including two test wipers for testing said trunk lines in pairs, means for releasing CHARLES J, E RICKSON.

said switch, and means for rendering said 10 testing means inefi'ective durin the release to prevent any false operation 0 said switch in case the said testing means engages a busy trunk line.

Signed by me at Chicago, Cook County, 15 Illinois, this 1st day of September, 1920.

CHARLES J. ERIGKSON.

tion to normal to prevent any further operation of said rotary magnet in case any busy trunk line is encountered.

2. In a telephone system, trunk lines, an 5 automatic switch accessible to said lines, testing means in said switch for locating trunk lines not in use, said testing means including two test wipers for testing said trunk lines in pairs, means for releasing DISCLAIMER.

1,544 300.--0barles J. Erickson, Chicago, Ill, Amona'no TELEPHONE SYSTEMS. l atent dated June 30 1925. Disclaimer filed May 17 1926, by the patentee, the

'- assignee, Automatic Zea-trio 1m, consenting.

Hereby enters this disclaimer to. claims 1 and 2 in said specification, which are in the following words, to wit 1. In a telephone system, an automatic switch, trunk lines accessible thereto, a rotary magnet, a test relay for said switch, means for making certain trunk lines busy, means for operating said switch to test a pair of trunk lines simultaneously, a circuit for energizing said relay including grounded test contacts of busy trunk lines when said switch attem ts to make connection therewith to operate said rotary magnet to cause said switc to test another pair of trunk lines simultaneously, means for releasing said switclnand means for opening said first mentioned circuit during restoration to normal to prevent any further operation of said rotary magnet in case any busy trunk line is encountered.

2. In a telephone system, trunk lines, an automatic switch accessible to said lines, testing means in said switch for locating trunk lines not in use, said testing means including two test wipers for testing said trunk lines in pairs, means for releasing said switch, and means for renderin said testin means inefl'ective during the release to prevent any false operationoi said switcli in case the said testing means on ages a busy trunk line.

[Ofiic' Gazette June 8, 1926.]

DISCLAIMER.

1,54430(i.- 0M1*Zes J. Erickson, Chicago, Ill, AUTOMATIC TELEPHONE SYSTEMS.

iatent dated June 30 1925. Disclaimer filed May 17, 1926, by the patentee, the assignee, Automatic lectrz'c 11w consenting.

Hereby enters this disclaimer to claims 1 and 2 in'said specification, which are in the followingwords, to wit: j

1. In a telephone system, an automatic switch, trunk lines accessible thereto, a rotary magnet, 11 test relay for said switch, means for making certain trunk lines busy, means for operating said switch to test a pair of trunk lines simultaneously, a circuit for energizing said relay including grounded test contacts of busy trunk lines when said switch attem ts to make connection therewith to operate said rotary magnet to cause said switc to test another pair of trunk lines simultaneously, means for releasing said switch antl means for opening said first mentioned circuit during restoration to normal to prevent any further operation of said rotary magnet in case any busy trunk line is encountered.

2. In a telephone system, trunk lines, an automatic switch accessible to said lines, testing means in said switch for locating trunk lines not in use, said testing means including two test wipers for testing said trunk lines in pairs, means for said switch, and means for renderin said testin means ineffective during the release to prevent any false operationo? said switch in case the said testing means engages a busy trunk line.-

[Oyficial Gazette June 8, 1926.] 

